Rant mode on. Stupid designer/engineers. The new 2017-2018 3.6 Colorado/Canyons have an issue with oil leaks from the engine oil cooler hoses and radiators. Root cause was found to be defective oil pump pressure relief valve design. Testing has found that during cold start/cold temperatures the valve can stick shut and the pump produces in excess of 1600 psi!! That much pressure is tearing the lining of the hoses out and pinholes develop spraying oil all over. Some have also blown the oil cooler out inside the radiator.
I've had the "pleasure" of fixing several of these so far. I can't even begin to explain the stupidity and lack of thought process these things are being built with. The oil pump is located at the rear and is driven via a long jack-shaft and gear set with a chain and sprocket off the front of the crank. First one I did (following GM's wonderful instructions) took me about 10 hours and I was ready to quit. The second one I did it "my way" and took me about 7 hours and a lot less frustration. Warranty time is 9.0 hours for the pump plus some added straight time for replacing the hoses. I have done several more since then and shaved even more time and unnecessary steps each time. I did one this morning, started at 7:30 AM and completed with de-greasing, and 5 mile road test just before noon.
So it's great money for me at this point I guess, just unnecessary and very aggravating to see this on a new from the ground up design.

"The spirit of resistance to government
is so valuable on certain occasions,
that I wish it to be always kept alive.
It will often be exercised when wrong,
but better so than not to be exercised at all.
I like a little rebellion now and then." -Thomas Jefferson (1743-1826)

Am I correct in my assessment that it seems like the 3.6 is becoming a VERY troublesome engine? Or am I only hearing about the bad ones with lots of good ones out there?

I really really like the new Coly/Can's. SERIOUSLY considered buying one before I bought my most recent F150. Although I was more interested in the 2.8 VM Motori diesel version. But just wasn't a fan of the seats and decided to stick with the ultra comfortable F150 platform that I was already familiar with.
Hey Mitch, out of curiosity how are the 2.8 diesel's doing on the dealer tech side?

Slept on this.. 1600 psi?? Gotta give it to the guy that designed the pump!

With that amount of pressure are there any mechanical issues coming from it? Peeling bearings, ballooned castings, etc? Just remember the fun with the input drums on the 4l60e, couldn't imagine what that pressure would've done to it.

Am I correct in my assessment that it seems like the 3.6 is becoming a VERY troublesome engine? Or am I only hearing about the bad ones with lots of good ones out there?

I really really like the new Coly/Can's. SERIOUSLY considered buying one before I bought my most recent F150. Although I was more interested in the 2.8 VM Motori diesel version. But just wasn't a fan of the seats and decided to stick with the ultra comfortable F150 platform that I was already familiar with.
Hey Mitch, out of curiosity how are the 2.8 diesel's doing on the dealer tech side?

It may be that it shows up because this engine is being used so much. It also has been redesigned several times but it doesn't seem like the engineers are interested in improvements, just changes for the sake of justifying salaries.
I don't deal with diesels, I have seen a few in the shop but I expect that with new models and engines first two years.

"The spirit of resistance to government
is so valuable on certain occasions,
that I wish it to be always kept alive.
It will often be exercised when wrong,
but better so than not to be exercised at all.
I like a little rebellion now and then." -Thomas Jefferson (1743-1826)

Slept on this.. 1600 psi?? Gotta give it to the guy that designed the pump!

With that amount of pressure are there any mechanical issues coming from it? Peeling bearings, ballooned castings, etc? Just remember the fun with the input drums on the 4l60e, couldn't imagine what that pressure would've done to it.

I know, that's hydraulic system pressures. Haven't seen any other issues caused by high pressures yet.

"The spirit of resistance to government
is so valuable on certain occasions,
that I wish it to be always kept alive.
It will often be exercised when wrong,
but better so than not to be exercised at all.
I like a little rebellion now and then." -Thomas Jefferson (1743-1826)